Keep quiet or act? Challenges in integrating ethical theory into gerontological nursing care during students' first clinical rotation: A discussion paper.

AIM: The aim of the paper is twofold: 1. To present observations based on first-year nursing students' narratives during clinical rotation in gerontological nursing care; and 2. Explore a nursing educator's reflections on these observations in relation to the didactic and ethical challenges that occurred. BACKGROUND: The teaching of ethics is included in nurse education worldwide. Students are in their first clinical placement in residential care of older persons confronted with the moral complexities of gerontological care, where they get little possibility to share emotions and thoughts about ethically challenging nursing situations with a supervising registered nurse. DESIGN: A critical discussion paper. METHOD: The educator's reflections in this discussion paper are based on a narrative assignment in ethics where first-year nursing students reflect on and describe a nursing situation during their clinical rotation in the residential care of older persons. RESULTS: Most students were acting as mere spectators in the described nursing situation where an older person, ethical standards, or evidence-based care was violated. Some students acted as advocates to the older person and intervened in the situation and a few as inspirers showing alternative ways of handling ethically challenging situations. CONCLUSIONS: Educators in nursing programs at the undergraduate level require time for student-centered formative guidance to foster moral courage and practice. During first-year students' clinical rotation, the learning goals in long-term residential care of older persons are focused on evidence-based basic nursing care. In this, students are confronted with ethically challenging situations, where the possibility to learn from a critical reflective practice is rare. When observing situations where an older person is subjected to unethical or unsafe nursing care it is common that the students take the spectators' role, not knowing how to deal with what is observed. Some students are taking an intervening role by trying to alleviate the vulnerability of the older person. A few are showing moral courage by directly intervening when experiencing unethical or unsafe nursing care or conduct. In this the student can inspire fellow students or staff during their clinical rotation in alternative ways of handling ethically challenging situations. As older persons are the largest demographic group that nurses will experience, educators need a sound knowledge of ethics as well as gerontological care to be able to meet and nurture students' ethical reflections during clinical practice and to foster practical wisdom in nursing.

Platinum vaporization-deposition coated polycarbonate membranes for comprehensive, multimodal, and correlative microscopic analysis of micro-and nanoplastics and other environmental particles.

Anthropogenic particles, including microplastics, are receiving ever-increasing concern due to their potential environmental impact. Surveys and monitoring require sampling from many environmental and biological matrices, including natural water, drinking water, sediment, and air. However, there are no standard methods for sampling particles in the environment; thereby, many different approaches are used for both single particle and ensemble distribution or bulk chemical analyses. In the microplastics field, particles are often analyzed on membranes using automated analysis with spectroscopic techniques such as Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. For automated analysis, the filters' properties are crucial. We coated polycarbonate (PC) membranes with 100 nm platinum (Pt) on both side using a e-beam evaporator and evaluated their suitability for filtrating and analysis of environmental samples. The PC membranes have a defined and practical pore size, available in many pore sizes and with circular diameter of 47 mm and 25 mm. Our Pt coated membranes can handle large volumes of fresh and marine waters, high pressure, and various treatment solutions. Moreover, they have good optical properties for imaging with light microscopy (LM) and Scanning Electron Microscopy (SEM), and no disturbing background signal for Raman or FTIR spectroscopy analysis.

Training the next generation of plastics pollution researchers: tools, skills and career perspectives in an interdisciplinary and transdisciplinary field.

Plastics pollution research attracts scientists from diverse disciplines. Many Early Career Researchers (ECRs) are drawn to this field to investigate and subsequently mitigate the negative impacts of plastics. Solving the multi-faceted plastic problem will always require breakthroughs across all levels of science disciplinarity, which supports interdisciplinary discoveries and underpins transdisciplinary solutions. In this context, ECRs have the opportunity to work across scientific discipline boundaries and connect with different stakeholders, including industry, policymakers and the public. To fully realize their potential, ECRs need to develop strong communication and project management skills to be able to effectively interface with academic peers and non-academic stakeholders. At the end of their formal education, many ECRs will choose to leave academia and pursue a career in private industry, government, research institutes or non-governmental organizations (NGOs). Here we give perspectives on how ECRs can develop the skills to tackle the challenges and opportunities of this transdisciplinary research field and how these skills can be transferred to different working sectors. We also explore how advisors can support an ECRs' growth through inclusive leadership and coaching. We further consider the roles each party may play in developing ECRs into mature scientists by helping them build a strong foundation, while also critically assessing problems in an interdisciplinary and transdisciplinary context. We hope these concepts can be useful in fostering the development of the next generation of plastics pollution researchers so they can address this global challenge more effectively.

Unraveling the Marine Microplastic Cycle: The First Simultaneous Data Set for Air, Sea Surface Microlayer, and Underlying Water.

Microplastics (MP) including tire wear particles (TWP) are ubiquitous. However, their mass loads, transport, and vertical behavior in water bodies and overlying air are never studied simultaneously before. Particularly, the sea surface microlayer (SML), a ubiquitous, predominantly organic, and gelatinous film (<1 mm), is interesting since it may favor MP enrichment. In this study, a remote-controlled research catamaran simultaneously sampled air, SML, and underlying water (ULW) in Swedish fjords of variable anthropogenic impacts (urban, industrial, and rural) to fill these knowledge gaps in the marine-atmospheric MP cycle. Polymer clusters and TWP were identified and quantified with pyrolysis-gas chromatography-mass spectrometry. Air samples contained clusters of polyethylene terephthalate, polycarbonate, and polystyrene (max 50 ng MP m-3). In water samples (max. 10.8 µg MP L-1), mainly TWP and clusters of poly(methyl methacrylate) and polyethylene terephthalate occurred. Here, TWP prevailed in the SML, while the poly(methyl methacrylate) cluster dominated the ULW. However, no general MP enrichment was observed in the SML. Elevated anthropogenic influences in urban and industrial compared to the rural fjord areas were reflected by enhanced MP levels in these areas. Vertical MP movement behavior and distribution were not only linked to polymer characteristics but also to polymer sources and environmental conditions.

Comparison of pre-treatment methods and heavy density liquids to optimize microplastic extraction from natural marine sediments.

The ubiquitous occurrence of anthropogenic particles, including microplastics in the marine environment, has, over the last years, gained worldwide attention. As a result, many methods have been developed to estimate the amount and type of microplastics in the marine environment. However, there are still no standardized protocols for how different marine matrices should be sampled or how to extract and identify these particles, making meaningful data comparison hard. Buoyant microplastics are influenced by winds and currents, and concentrations could hence be expected to be highly variable over time. However, since both high density and most of the initially buoyant microplastics are known to eventually sink and settle on the seafloor, marine sediments are proposed as a suitable matrix for microplastics monitoring. Several principles, apparatuses, and protocols for extracting microplastics from marine sediments have been presented, but extensive comparison of the different steps in the protocols using real environmental samples is lacking. Thus, in this study, different pre-treatment and subsequent density separation protocols for extraction of microplastics from replicate samples of marine sediment were compared. Two pre-treatment methods, one using inorganic chemicals (NaClO + KOH + Na4P2O7) and one using porcine pancreatic enzymes, as well as one with no pre-treatment of the sediment, were compared in combination with two commonly used high-density saline solutions used for density separation, sodium chloride (NaCl) and zinc chloride (ZnCl2). Both pre-treatment methods effectively removed organic matter, and both saline solutions extracted lighter plastic particles such as polyethylene (PE) and polypropylene (PP). The most efficient combination, chemical pre-treatment and density separation with ZnCl2, was found to extract > 15 times more particles (≥ 100 µm) from the sediment than other treatment combinations, which could largely be explained by the high presence and efficient extraction of PVC particles.

Teaching Gerontology in Transcultural Academics: A Phenomenographic Study of Thai and Swedish Nurse Educators' Conceptions of Gerontological Nursing.

INTRODUCTION: There is an urgent need for registered nurses with gerontological competence within long-term care (LTC) of older adults. Despite increases of life expectancy, LTC for older adults is not emphasized in nursing curricula in neither Sweden nor Thailand. Thus, the aim was to explore conceptions on gerontological nursing (GN) among Swedish and Thai nurse educators. METHOD: A qualitative phenomenographic method, based on open-ended interviews with five Thai and nine Swedish nurse educators was conducted. RESULTS: The results indicate a paradox between the educators' knowledge about the implications of global aging, their hope of own aging, and LTC. The ethical responsibility of being credible and a source of inspiration in teaching about aging are focused, while GN seem to be less important. DISCUSSION: To increase students' interest in GN, measures need to be taken within the educational arenas, where the educators' own conceptions toward GN, cultural aspects of aging, and LTC are discussed.

Deep Learning for Reconstructing Low-Quality FTIR and Raman Spectra─A Case Study in Microplastic Analyses.

Herein we report on a deep-learning method for the removal of instrumental noise and unwanted spectral artifacts in Fourier transform infrared (FTIR) or Raman spectra, especially in automated applications in which a large number of spectra have to be acquired within limited time. Automated batch workflows allowing only a few seconds per measurement, without the possibility of manually optimizing measurement parameters, often result in challenging and heterogeneous datasets. A prominent example of this problem is the automated spectroscopic measurement of particles in environmental samples regarding their content of microplastic (MP) particles. Effective spectral identification is hampered by low signal-to-noise ratios and baseline artifacts as, again, spectral post-processing and analysis must be performed in automated measurements, without adjusting specific parameters for each spectrum. We demonstrate the application of a simple autoencoding neural net for reconstruction of complex spectral distortions, such as high levels of noise, baseline bending, interferences, or distorted bands. Once trained on appropriate data, the network is able to remove all unwanted artifacts in a single pass without the need for tuning spectra-specific parameters and with high computational efficiency. Thus, it offers great potential for monitoring applications with a large number of spectra and limited analysis time with availability of representative data from already completed experiments.

Analytical performance of a standardized kit for mass spectrometry-based measurements of human glycosaminoglycans.

Glycosaminoglycans (GAGs) are long linear sulfated polysaccharides implicated in processes linked to disease development such as mucopolysaccharidosis, respiratory failure, cancer, and viral infections, thereby serving as potential biomarkers. A successful clinical translation of GAGs as biomarkers depends on the availability of standardized GAG measurements. However, owing to the analytical complexity associated with the quantification of GAG concentration and structural composition, a standardized method to simultaneously measure multiple GAGs is missing. In this study, we sought to characterize the analytical performance of a ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-MS/MS)-based kit for the quantification of 17 free GAG disaccharides. The kit showed acceptable linearity, selectivity and specificity, accuracy and precision, and analyte stability in the absolute quantification of 15 disaccharides. In native human samples, here using urine as a reference matrix, the analytical performance of the kit was acceptable for the quantification of CS disaccharides. Intra- and inter-laboratory tests performed in an external laboratory demonstrated robust reproducibility of GAG measurements showing that the kit was acceptably standardized. In conclusion, these results indicated that the UHPLC-MS/MS kit was standardized for the simultaneous measurement of free GAG disaccharides allowing for comparability of measurements and enabling translational research.

Cross-cultural perspectives on gerontology in nursing education - a qualitative study of nurse educators' experiences.

This study focuses on nurse educators' perspectives on teaching gerontology within nursing curricula in two cultures. An increasing aging multi-cultural population with large caring needs requires not only informal elder care provided by family members, but also professional nursing staff trained in gerontology. The aim of this study was to explore how Swedish and Thai nurse educators describe the role of teaching gerontology within nursing educations in Sweden and Thailand. Method: Qualitative open-ended interviews with 13 Swedish and Thai nurse educators were conducted and analyzed with qualitative content analysis. Findings: There is a lack of gerontological nursing competence in faculty, as well as bureaucracy impeding necessary changes of curricula, together with difficulties in highlighting positive and cultural aspects of aging. Conclusions: Pedagogical strategies need to be developed by nurse educators specialized in cross-cultural gerontology to improve current and future nursing educations in both countries.

Prognostic role of serum thymidine kinase 1 activity in patients with hormone receptor-positive metastatic breast cancer: Analysis of the randomised phase III Evaluation of Faslodex versus Exemestane Clinical Trial (EFECT).

BACKGROUND: Thymidine kinase 1 (TK1) plays a critical role in DNA synthesis and cell proliferation. Recent studies have shown potential for serum TK1 activity (sTKa) as a prognostic marker and indicator of early response to endocrine therapy in advanced breast cancer. The aim of this study is to assess the correlation between sTKa and patient outcome. PATIENTS AND METHODS: The Evaluation of Faslodex versus Exemestane Clinical Trial (EFECT) was a double-blind, double-dummy, randomised trial of fulvestrant versus exemestane after progression on non-steroidal aromatase inhibitor therapy, in postmenopausal women with advanced breast cancer. Retrospective analyses of serum archived from EFECT were conducted. sTKa was assessed using the DiviTum® assay on samples collected at baseline, after three and six months of endocrine therapy, and at disease progression. RESULTS: The median time to progression (mTTP) for patients with low baseline sTKa levels was 5.03 months (95% confidence interval [CI]: 3.91-5.89) versus 2.57 months (95% CI: 2.04-3.52) in patients with high sTKa baseline levels (P < 0.0001). On treatment, patients whose sTKa increased from baseline had a significantly shorter mTTP (3.39 months, 95% CI: 2.14-4.11) than those without an sTKa increase (5.39 months, 95% CI: 4.01-6.68) (P = 0.0045). Similar results were observed in the separate EFECT treatment arms. After adjusting for major prognostic factors, sTKa remained an independent marker. CONCLUSION: sTKa is a potential circulating prognostic marker in patients with advanced breast cancer treated with endocrine therapy. It may also represent a tool for upfront identification of endocrine therapy resistance and early positive response to therapy. Independent validation of these results is warranted.

Disaggregation of gold nanoparticles by Daphnia magna.

The use of manufactured nanomaterials is rapidly increasing, while our understanding of the consequences of releasing these materials into the environment is still limited and many questions remain, for example, how do nanoparticles affect living organisms in the wild? How do organisms adapt and protect themselves from exposure to foreign materials? How does the environment affect the performance of nanoparticles, including their surface properties? In an effort to address these crucial questions, our main aim has been to probe the effects of aquatic organisms on nanoparticle aggregation. We have, therefore, carried out a systematic study with the purpose to disentangle the effects of the freshwater zooplankter, Daphnia magna, on the surface properties, stability, and aggregation properties of gold (Au) nanoparticles under different aqueous conditions as well as identified the proteins bound to the nanoparticle surface. We show that Au nanoparticles aggregate in pure tap water, but to a lesser extent in water that either contains Daphnia or has been pre-conditioned with Daphnia. Moreover, we show that proteins generated by Daphnia bind to the Au nanoparticles and create a modified surface that renders them less prone to aggregation. We conclude that the surrounding milieu, as well as the surface properties of the original Au particles, are important factors in determining how the nanoparticles are affected by biological metabolism. In a broader context, our results show how nanoparticles released into a natural ecosystem become chemically and physically altered through the dynamic interactions between particles and organisms, either through biological metabolism or through the interactions with biomolecules excreted by organisms into the environment.

Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain.

The tremendous increases in production of plastic materials has led to an accumulation of plastic pollution worldwide. Many studies have addressed the physical effects of large-sized plastics on organisms, whereas few have focused on plastic nanoparticles, despite their distinct chemical, physical and mechanical properties. Hence our understanding of their effects on ecosystem function, behaviour and metabolism of organisms remains elusive. Here we demonstrate that plastic nanoparticles reduce survival of aquatic zooplankton and penetrate the blood-to-brain barrier in fish and cause behavioural disorders. Hence, for the first time, we uncover direct interactions between plastic nanoparticles and brain tissue, which is the likely mechanism behind the observed behavioural disorders in the top consumer. In a broader perspective, our findings demonstrate that plastic nanoparticles are transferred up through a food chain, enter the brain of the top consumer and affect its behaviour, thereby severely disrupting the function of natural ecosystems.

Teaching gerontology in globalized academics: a qualitative study of Thai nursing students' views on ageing when studying abroad.

BACKGROUND: Negative views towards ageing and older adults may be a reason why nurses do not choose to work in gerontological nursing. Studying in another cultural context can challenge these views. The Objective was to explore nursing students' views on ageing and older adults before and after a gerontology course held abroad. DESIGN AND METHOD: A qualitative approach based on content analysis of responses to open-ended questions by 30 Thai nursing students studying a gerontology course in Sweden. RESULTS: Three main categories: positive imprints of ageing, ageing takes its toll, and knowledge leading to action, emerged through sub-categories carrying a view of older adults as not only in need of care, but also as resourceful and competent. Professional healthcare, besides family was seen as potential caregivers in old age. CONCLUSIONS: Studying gerontology abroad can widen views towards ageing and older adults, inspiring nurses to work in gerontological nursing.

Translocation of 40 nm diameter nanowires through the intestinal epithelium of Daphnia magna.

Nanowires (NWs) have unique electrical and optical properties of value for many applications including lighting, sensing, and energy harnessing. Consumer products containing NWs increase the risk of NWs being released in the environment, especially into aquatic ecosystems through sewage systems. Daphnia magna is a common, cosmopolitan freshwater organism sensitive to toxicity tests and represents a likely entry point for nanoparticles into food webs of aquatic ecosystems. Here we have evaluated the effect of NW diameter on the gut penetrance of NWs in Daphnia magna. The animals were exposed to NWs of two diameters (40 and 80 nm) and similar length (3.6 and 3.8 µm, respectively) suspended in water. In order to locate the NWs in Daphnia, the NWs were designed to comprise one inherently fluorescent segment of gallium indium phosphide (GaInP) flanked by a gallium phosphide (GaP) segment. Daphnia mortality was assessed directly after 24 h of exposure and 7 days after exposure. Translocation of NWs across the intestinal epithelium was investigated using confocal fluorescence microscopy directly after 24 h of exposure and was observed in 89% of Daphnia exposed to 40 nm NWs and in 11% of Daphnia exposed to 80 nm NWs. A high degree of fragmentation was observed for NWs of both diameters after ingestion by the Daphnia, although 40 nm NWs were fragmented to a greater extent, which could possibly facilitate translocation across the intestinal epithelium. Our results show that the feeding behavior of animals may enhance the ability of NWs to penetrate biological barriers and that penetrance is governed by the NW diameter.

Analysis of nanoparticle-protein coronas formed in vitro between nanosized welding particles and nasal lavage proteins.

Welding fumes include agglomerated particles built up of primary nanoparticles. Particles inhaled through the nose will to some extent be deposited in the protein-rich nasal mucosa, and a protein corona will be formed around the particles. The aim was to identify the protein corona formed between nasal lavage proteins and four types of particles with different parameters. Two of the particles were formed and collected during welding and two were manufactured iron oxides. When nasal lavage proteins were added to the particles, differences were observed in the sizes of the aggregates that were formed. Measurements showed that the amount of protein bound to particles correlated with the relative size increase of the aggregates, suggesting that the surface area was associated with the binding capacity. However, differences in aggregate sizes were detected when nasal proteins were added to UFWF and Fe2O3 particles (having similar agglomerated size) suggesting that yet parameters other than size determine the binding. Relative quantitative mass spectrometric and gel-based analyses showed differences in the protein content of the coronas. High-affinity proteins were further assessed for network interactions. Additional experiments showed that the inhibitory function of secretory leukocyte peptidase inhibitor, a highly abundant nasal protein, was influenced by particle binding suggesting that an understanding of protein function following particle binding is necessary to properly evaluate pathophysiological events. Our results underscore the importance of including particles collected from real working environments when studying the toxic effects of particles because these effects might be mediated by the protein corona.

Altered behavior, physiology, and metabolism in fish exposed to polystyrene nanoparticles.

The use of nanoparticles in consumer products, for example, cosmetics, sunscreens, and electrical devices, has increased tremendously over the past decade despite insufficient knowledge about their effects on human health and ecosystem function. Moreover, the amount of plastic waste products that enter natural ecosystems, such as oceans and lakes, is increasing, and degradation of the disposed plastics produces smaller particles toward the nano scale. Therefore, it is of utmost importance to gain knowledge about how plastic nanoparticles enter and affect living organisms. Here we have administered 24 and 27 nm polystyrene nanoparticles to fish through an aquatic food chain, from algae through Daphnia, and studied the effects on behavior and metabolism. We found severe effects on feeding and shoaling behavior as well as metabolism of the fish; hence, we conclude that polystyrene nanoparticles have severe effects on both behavior and metabolism in fish and that commonly used nanosized particles may have considerable effects on natural systems and ecosystem services derived from them.

The diverging perception among physiotherapists of how to work with the concept of evidence: a phenomenographic analysis.

RATIONALE, AIMS AND OBJECTIVES: Changes in Sweden's municipal care have impacted the situation of physiotherapists by the adoption of practice based on research evidence. Even if physiotherapists appear to be in favour of the idea of evidence-based practice, barriers still exist that prevent many from keeping up with current research. The aim of this study was to identify and describe the different ways in which physiotherapists in municipal care perceive the concept of evidence in rehabilitation. METHODS: A phenomenographic design with semi-structured interviews was carried out with physiotherapists working with frail older people in three municipal care units in two neighbouring municipalities in Sweden. The physiotherapists' perceptions of evidence were explored in 12 interviews. RESULTS: Distinct perceptions of the concept of evidence are identified in three categories: 'Confidence with the concept of evidence in relation to measurement instruments'; 'Perception of evidence-based practice as a duty, condition and demand of the profession'; and 'Evidence-based work as a separate rather than directly patient-oriented activity'. CONCLUSIONS: Physiotherapists take full responsibility to comply with what they perceive to be the demands of their profession. However, what evidence actually meant, and therefore what the practical element of this responsibility consisted of, was not as clear.

Aspects of nursing with evidence-base when nursing frail older adults: a phenomenographic analysis of interviews with nurses in municipal care.

INTRODUCTION: In earlier research as well as in political discussion and documents, the topic of evidence has been highlighted as one of the most important concerns in nursing care. This study focuses on understanding what lies behind nurses' ways of acting regarding evidence-based nursing through an illumination of the way they perceive the phenomena. AIM: The aim was to identify and describe the different ways municipal care nurses perceive aspects of working with evidence when nursing frail older adults. METHODS: An explorative design with a phenomenographic approach based on interviews with nurses working with home-based care within the municipality was used in order to gain understanding of nurse's perceptions of the phenomena. RESULTS: Findings revealed that the nurses perceived a variety of aspects when working with evidence when nursing frail older people. Aspects with a spectra of different perceptions shown in the analysis were as follows: Evidence-based nursing as a desired intention/mission, lack of practical supporting structures to apply evidence, lack of confidence in own capacity to apply evidence and a belief that it will work anyway. CONCLUSIONS: Findings reveal that it is a challenge to implement research both on an individual as well as on an organisational level. Understanding the contextual perceptions of evidence by nurses can cast light on the barriers as well as the prerequisites of working with evidence while caring for frail older adults in municipal care.

HHV-8 encoded LANA-1 alters the higher organization of the cell nucleus.

The latency-associated nuclear antigen (LANA-1) of Human Herpes Virus 8 (HHV-8), alternatively called Kaposi Sarcoma Herpes Virus (KSHV) is constitutively expressed in all HHV-8 infected cells. LANA-1 accumulates in well-defined foci that co-localize with the viral episomes. We have previously shown that these foci are tightly associated with the borders of heterochromatin 1. We have also shown that exogenously expressed LANA-1 causes an extensive re-organization of Hoechst 33248 DNA staining patterns of the nuclei in non-HHV-8 infected cells 2. Here we show that this effect includes the release of the bulk of DNA from heterochromatic areas, in both human and mouse cells, without affecting the overall levels of heterochromatin associated histone H3 lysine 9 tri-methylation (3MK9H3). The release of DNA from the heterochromatic chromocenters in LANA-1 transfected mouse cells co-incides with the dispersion of the chromocenter associated methylcytosin binding protein 2 (MECP2). The localization of 3MK9H3 to the remnants of the chromocenters remains unaltered. Moreover, exogeneously expressed LANA-1 leads to the relocation of the chromocenters to the nuclear periphery, indicating extensive changes in the positioning of the chromosomal domains in the LANA-1 harboring interphase nucleus. Using a series of deletion mutants we have shown that the chromatin rearranging effects of LANA-1 require the presence of a short (57 amino acid) region that is located immediately upstream of the internal acidic repeats. This sequence lies within the previously mapped binding site to histone methyltransferase SUV39H1. We suggest that the highly concentrated LANA-1, anchored to the host genome in the nuclear foci of latently infected cells and replicated through each cell generation, may function as "epigenetic modifier". The induction of histone modification in adjacent host genes may lead to altered gene expression, thereby contributing to the viral oncogenesis.

HFRS causing hantaviruses do not induce apoptosis in confluent Vero E6 and A-549 cells.

Hantaviruses are known to cause little or no cytopathic effect in vitro, but have been suggested to cause apoptosis. To determine whether different hantaviruses would induce apoptosis to varying degrees, confluent Vero E6 cells were infected with the hemorrhagic fever with renal syndrome (HFRS) causing viruses Hantaan, Dobrava, Saaremaa, and Puumala. However, no difference was found in the percentage of adherent cells, or of cells with condensed nuclei, between non-infected and virus-infected cells at 3, 6, 9, or 12 days after infection. Furthermore, no differences in the percentage of cells with inter-nucleosomal cleavage of DNA between uninfected and Hantaan infected cells could be detected using the TUNEL assay. Possibly, slightly more apoptotic cells, but never more than 5%, were detected after Hantaan infection of non-confluent cells as compared to the negative control. Earlier reported results that Tula hantavirus induces significant apoptosis on Vero E6 cells were also verified, suggesting that non-pathogenic hantaviruses might differ from HFRS-causing strains regarding induction of apoptosis. In conclusion, the results indicated that the HFRS-causing hantaviruses might induce a very low level of apoptosis in dividing cells, but not at all in confluent cells.